Anchor



Feb. 27, 1962 c. w. HILLCOURT ANCHOR Filed Dec. 14, 1959 INVENTOR CARROLW. H/LLCOURT ATTORNEYS 3,022,762 ANCHOR Carroi W. Hillcourt, 342 LibertySt., San Francisco, Calif. Filed Dec. 14, 1959, Ser. No. 859,261 9Claims. (Cl. 114-2il8) This invention relates to an anchor for boats,and more particularly to an anchor having a fluke pivotally carried on ashank for burrowing into the sand or mud at the sea floor and wedgetherein against displacement. This application is a continuation-in-partof my copending application Serial No. 773,236 filed November 12, 1958,now abandoned.

It is an object of this invention to provide an anchor combining theadvantages of minimum weight with maximum holding power.

It is a further object of this invention to provide an anchor having apivoted fluke capable of expeditious penetration into the sea floorwhile presenting a maximum vertical area of resistance againstdisplacement.

It is a further object of this invention to provide an anchor thatburrows easily into the sea floor and holds rigidly against displacementbut which may be easily removed and raised when it is desired to do so.

it is a further object of this invention to provide an anchor that is'simple in construction and reliable in operation.

An anchor constructed in accordance with this invention includes anelongate shank to one end of which is secured the anchor line. At theother end of the shank is pivotally mounted a fluke having a burrowingtip and a relatively wide base from which there extends a pair ofrearwardly diverging tail plates forming a wedge at the trailing end ofthe fluke. The fluke is pivotable on the shank about an axis rearward ofthe apex of the tail plate wedge so that a maximum portion of the tailplate surface will be pivoted below the level of the shank which issupported on the sea floor. Stop means limit the pivotal movement of thefluke to a relatively small angle so that the fluke penetrates rathereasily into the substance of the sea floor under the generallyhorizontal forces that are extended along the anchor line by surfaceforces tending to move the boat. Once resistance to penetration isovercome a steeper Wedging angle is introduced to burrow deeper and topresent a more nearly vertical surface in engagement with the sand ormud of the sea floor in opposition to displacement by the horizontalforce. Because the displacing force is in a generally horizontaldirection the capacity of the fluke to resist displacement isproportionate to the vertical projected area of the fluke. Hence, thenear vertical disposition of the tail plate wedge affords near maximumholding capacity per area thereof. The fluke is pivoted about an axisdisplaced rearwardly of the wedge so that a maximum area of the tailplate wedge will pivot below the shank to penetrate into the sea door.The stop means for limiting pivotal movement of the fluke are alsoarranged as far to the rearward end of the shank as is possible in orderto achieve maximum mechanical advantage for removal of the anchor. Thatis, with the connection between the shank and the fluke, i.e. the stopmeans, near one end of the shank and the connection to the anchor lineat the other end of the shank the resultant long lever arm facilitatesremoval under upward pull to pivot the fluke with the shank free of themud.

Other objects and advantages of my invention will become apparent fromthe specification following when read in connection with theaccompanying drawings wherein:

FIG. 1 is an isometric view of a preferred form of anchor embodyingfeatures of my invention;

1 FIG. 2 is a vertical section view of the anchor of FIG.

; and

FIG. 3 is an isometric view of an alternate form of anchor embodyingfeatures of my invention.

Referring now to the drawings in greater detail, the preferred form ofanchor 1 has ashank 2 having a hole 3 in one end thereof to carry ashackle 4 for attachment of the anchor to an anchor line 5 secured tothe buoyant craft afloat at the surface.

Preferably, the shank 2 is of yoke configuration having branched arms 6between the extremities of Whichis fixed a rod or shaft '7. A second rod8 spans the spaced arms 6, being secured rigidly thereto forward of theshaft 7, and thus contributes to the rigidity of the shank 2.

The fluke 10 is made up of a rigid plate 11, preferably of generallytriangular configuration having a pointed tip 12 forburrowing into thesand or mud of the sea floor. Secured to and diverging rearwardly fromopposite sides of the face of the triangular plate 11 are a pair of tailplates 14 which together form a wedge having its apex 15 along the baseof the fluke plate 11. Strengthening ribs 16 may be welded or otherwiserigidly se-' cured to the fluke plate. lland to the diverging tailplates 14 to rigidify the structure.

The composite fluke 10 is pivotally mounted on the shank 2 about theshaft 7 and is disposed relative thereto so that the shaft 7 lies in theplane of the fluke plate 11 and is parallel to and spaced rearwardlyfrom the apex 15 of the composite wedge formed bythe tail plates 14. Inthe preferred embodiment shown in FIGS. 1 and 2 the shaft 7 is locatedin such position relative to the fluke plate 11 and tail plates 14, byrigidly securing to the diverging tail plates 14 a pair of rearwardlyextending bearing brackets 24) which rotatably receive the shaft 7. Forsimplicity of construction, the brackets may simply be cast with alignedholes 21 formed therein rotatably to receive the shaft 7 secured betweenthe arms 6 of the shank 2. The brackets 20 also include arcuate openings22 which terminate in stop. surfaces 23, to receive the rod 8 so thatengagement of the rod 8 with the stop surfaces defines the limit ofpivotal movement of the fluke 10 about the shaft 7.

In actual use, the anchor 1 is pulled by a force F on the anchor linealong a generally horizontal line with the anchor shank 2 beingsupported by the sea floor in v a generally horizontal disposition.Thus, the angle a that the fluke plate 11 makes with the axis 25 of theshank 2 determines the angle of entrance of the fluke plate 11 into thesea floor. I have found that the rod 8 and stop surfaces 23 ofthebearing frame should be arranged so that the angle ofentrance of thefluke-should be in the range from 25 to 55 and preferably about 35. Anangle of entry of about 35 is small enough that the generally horizontalforce F has a substantial component along the plane of the fluke plate11. Moreover, at approximately 35 the mechanical advantage is highthereby to facilitate penetration. At the same time, the inclination ofthe fluke plate 11 is steep enough to direct penetration downward and topresent a substantial efiective vertical surface, as indicated inphantom projection V 1a, against which the horizontal displacementresisting forces 1 act.

Similarly, the angle 0 at which each tail plate 14 is disposed relativeto the plane of the fluke plate 11 should also be in the range from 25to 55, and preferably about 35. With each wedge-like tail plate 14diverging at an angle of 35 the upper tail plate assumes a 70 angle ofentry into the sea floor while the fluke plate is pivoted to 35 from theshank axis 25 which corresponds generally to the level of the sea floor.Once the inertia of resistance to penetration is overcome and the flukeis burrowing into the sea floormud the steep upper diverging wedgeplatel4 delivers a final downward wedging thrust firmly to anchor the flukeinto the sand. At the same time the broad wedge-like configuration ofthe diverging tail plates tends to limit the penetration of the anchorand prevent it from going too deep into the sea floor. As pointed out,the holding power'is dependent upon a vertical projection of the areaand burying the anchor too deeply merely hinders its'removal undervertical force. The increased slope of the upper wedging tail plateproduces a vertical projected area 14a of almost full size to achievemaximum anchoring force distributed thereover and represented by thearrows f. The effectof the steep angle of the upper wedge isparticularly significant in the case of the tail plates 14 since theyare of full width and hence, of maximum area per unit depth ofpenetration.

With the pivotal axis 7 spaced rearwardly from the apex 15 of thecomposite wedge formed by the tail plates 14, virtually all of the areaof upper tail plate 14 will be pivoted below the level of the shank andhence driven into the sea floor upon which the shank 2 is supported.Hence, maximum displacement resisting area is activated by penetrationinto the sea floor. Moreover, since virtually all of the tail platesurface 14 is below the level ofthe pivot shaft 7, no opposing momentarm is presented which would otherwise tend to pivot the fluke 10 up-:ardly under the mud forces f and thereby reduce the wedges should belarge enough to achieve maximum projected area 14a, but small enough toachieve the downward driving force to complete the anchoring action. Inthis connection, it is obvious that it is desirable to have the entryangle of the wedge 15 relative to the direction of force F less than 90because when the angle exceeds 90 there will be a resultant resistanceto forward movement and no tendency to drive the fluke 10 downward inresponse thereto.

While experiments indicate that optimum performance can be realized withthe angle on and 6' set at about 35 it is obvious that the desiredpurposes can be achieved over a reasonable range of angles. For example,with the angles a and 6 set at 30, the entrance angle of the upper tailplate will be 60 and when they both are at 40, the entrance .angle ofthe tail plane will be 80". In both instances reasonable wedging actionand satisfactory vertical area projection may be realized. It is not tobeimplied, however, that the angles or and 0 need be identical; thedesigner can depart from the preferred angles stated in any way within areasonable range that 1 enables him to achieve a satisfactorycombination of good penetration and suitable holding capacity.

When it is desired to raise the anchor, tension is applied to the anchorline 5 in the usual manner to move the craft to a position above theanchor. With the lifting force F now in a vertical direction, the anchoris pivoted about the rearward end thereof, as for example the rearwardedge of the lower tail plate 14. The rod 8 and stop portions 23 of thebearing member function as a oneway clutch to pivot the fluke 10 withthe shank 2. Since the engagement of the'elements 8, 23 is closelyadjacent to the rearward end of the anchor and the raising force F is atthe opposite end, the load of the fiuke is carried by the shank at avery large mechanical advantage. The long lever arm facilitates removalof the anchor under vertical force F If desired removal of the anchormay be further facilitated by providing an opening 26 in the fluke 11 topermit release of any vacuum that may be created between the plate 11and the mud of the sea floor.

l have found that the yoke type 2 is most satisfactory because itprovides maximum strength; because it tends to lie fiat on the seafloor; and because it enables the use of a single, large surfaced fluketherewith. However, it is to be understood that a split fluke could beused in conjunction with a single bar shank according to the rinciplesof this invention with satisfactory results.

While it is preferred to have the pivotal axis of the fluke spacedrearward from the apex of the diverging tail plates so as to swing theentire mea of the upper tail plate below the surface of the sea floor, Ihave achieved satisfactory anchoring by locating the pivotal axisimmediately behind the apex 15b as shown in the embodiment of PEG. 3.There, a shaft 7b may be welded directly to the junctureof' the tailplates 14b and thefiuke triangular plate 11!) and rotatably carriedbetween the spaced arms 6 of the shank 2. In this, as in the otherembodiment, the stop 8b may operate directly upon the portions on thediverging tail plates 14b to limit the angle of entrance of the flukeplate 11b. Again, a vacuum relieving opening 261') may be provided ifdesired.

While I have described preferred embodiments of this invention, it isapparent that modifications and changes can be made therein withoutdeparting from the spirit and scope of this invention which is definedin the claims appended hereto. f

Having described my invention, I claim:

1. An anchor comprising: an elongate yoke-like shank having divergingarms and connecting means at the closed end thereof for attachment to ananchor line, a fluke having a base and a burrowing tip, rearwardlydiverging tail'sections on said fluke forming a Wedge with the apexthereof secured to and extending along said base, journal means mountingsaid fluke on the other end of said shank between said arms for pivotalmovement about an axis generally parallel to and rearward of said apex,and cooperating stop means on said shank and said tail sections to limitthe extent of said pivotal movement in opposite directions, said tailsections being disposed at angles relative to said fluke so that whensaid shank is generally horizontally disposed the angle of the upper oneof said tail plates relative to said shank is less than 9i) degrees whensaid pivotal movement is limited by said stop means.

2. An anchor comprising: an elongate yoke-like shank having divergingarms and connecting means at the closed end thereof for attachment to ananchor line, a fluke having a relatively wide base and a burrowing tipmounted between said arms adjacent the other end of said shank forpivotal'movement thereon, rearwardly diverging tail sections onsaidfiuke forming a rigid wedge with the apex thereof extending alongsaid base, said tail sections being secured directly to said fluke eachto form a continuation of one side of said fluke, said fluke beingpivoted about an axis extending substantially parallel to said base andintermediate the planes of said tail sections, and stop means on saidshank between the planes of said tail sections engaeable with portionsthereon to limit the extent of said pivotal movement.

3. An anchor comprising a fluke having a bottom-engaging tip and arelatively wide base, diverging tail sections on said fluke formingawedge with the apex of said Wedge at said base, an elongated shankhaving an extremity beyond said tip with an eye for connection to ananchor line, branched arms of said shank extending from said extremityadjacent to but spaced from the edges of said fluke, and a pivotalconnection between said branched arms and said fluke adjacent to saidbase to provide pivotal movement about an axis parallel to the length ofsaid base, said arms of said shank extending on both sides of saidpivotal connection with the portion of said arms on one side of saidpivotal connection lying between the plane of said diverging tailsections, and having a connecting bar between such portions of said armsproviding a stop between said tail sections to limit the extent ofpivotal movement of said shank with respect to said fluke.

4. The anchor defined in claim 3 wherein said fluke has an openingtherethrough to enable ready release of said anchor from muddy bottomsby upward pull on said shank.

5. An anchor comprising: an elongate shank having means at one endthereof for attachment to an anchor line, a fluke having a relativelywide base and a burrowing tip, rearwardly diverging tail plates rigidlysecured to said fluke and forming a wedge with the apex thereofextending along said base, journal means pivotally mounting said flukeon the other end of said shank for pivotal movement about an axisparallel to and rearward of said apex, and stop means on said shankbetween the planes of said tail plates engageable with portions theretonto limit the extent of said pivotal movement in opposite directions,said axis being spaced rearward from said apex far enough that when saidshank is generally horizontally disposed and said fluke is pivoteddownward to the full extent limited by said stop means a substantialportion of the upper one of said tail plates is disposed below the planeof said shank, said tail plates being disposed at angles relative tosaid fluke so that the angle of said upper tail plate relative to saidshank cannot exceed 90 degrees.

6. The anchor defined in claim 5 wherein the angle between saiddiverging tail sections is less than 90.

7. The anchor defined in claim 6 wherein said stop means are arranged tolimit said pivotal movement of the fluke in each direction to an angleless than 45 relative to said shank.

8. The anchor defined in claim 5 wherein said tail plates are disposedon opposite sides of said plane of the fluke each at an angle thereto ofsubstantially 9. The anchor defined in claim 8 wherein said stop meansare disposed relative to said portions so as to limit the extent of thepivotal movement of said fluke to 35 on each side of said shank.

References Cited in the file of this patent UNITED STATES PATENTS2,282,566 Danforth May 12, 1942 2,696,187 Pitzipio Dec. 7, 1954 FOREIGNPATENTS 617,367 Great Britain Feb. 4, 1949 647,932 Great Britain Dec.28, 1950

